Future Earth

Steve Dutch

University of Wisconsin-Green

Bay

Why Look Ahead?

• Usually picture geologic time by looking back

• New Perspective

• Can you picture the U.S. in 1000 years?

• That’s an instant in geologic time

• Human activities are ephemeral compared to geologic time

1000 Years

• 5-7 M=8 quakes on San Andreas

• New Madrid and Cascadia quakes

• 10 Cascades eruptions

• Mississippi delta shift

• Niagara Falls retreats 900 meters

• Hawaii moves 90 meters

• Probable damaging meteor impact

• One or more supernovas

Humans in 1000 years

• Probably many cities and nations will still be extant

10,000 years• 50-70 M=8 quakes on San Andreas• 100 Cascades eruptions• 10-20 Mississippi delta shifts• Niagara Falls retreats 9 kilometers• Hawaii moves 900 meters• Probable meteor impact with regional

effects• Hudson’s Bay and Baltic drained• Dozens of Supernovas• Earth axis tilt 22-1/2 degrees

Future Niagara Falls

Past and Future

Niagara Falls

Humans in 10,000 years

• In 8,000 years we got from proto-Indo-European to English, Latin and Russian

• Time enough for new languages to evolve

• Will any word in any language still survive?

100,000 years• San Andreas shifted by 2.5 kilometers

• 1000 Cascades eruptions

• 100-200 Mississippi delta shifts

• Niagara Falls retreated to Lake Erie

• Loihi reaches surface?

• Numerous meteor impacts with regional effects probable

• Next ice age?

• New stars may form

The Future Gulf

Coast

Stars Change Faster

than the Earth

Humans in 100,000 years

• Time enough to develop our civilization from Paleolithic technology

• Fewer natural resources but…

• Old human deposits may be better sources than rocks

1,000,000 years• San Andreas shifted by 25 kilometers• Large new Cascades volcanoes• 1000-2000 Mississippi delta shifts• Ten ice ages?• Loihi and Kilauea as large as present

Mauna Loa• Several collapses of Hawaiian shields• Several supervolcano eruptions• Meteor impact with global effects probable

The Future San Andreas

Bright Stars in the next Million Years

Humans in 1,000,000 years

• Human race itself may evolve

• If society collapses long enough, different gene pools may speciate

What Will Endure 1,000,000 years?• Steel corrodes

• Titanic and Arizona will be gone in 1000 years.

• Most likely to survive: no steel, solid– Highway and canal cuts– Earth fill dams– Open pit mines and mine dumps– Large monuments (Mount Rushmore,

Pyramids)

What Will They See of Us?• Pleistocene mass extinction• Rapid global spread of human artifacts,

reduction of forests, and spread of domestic animals

• Sixth Extinction?– Many endangered organisms would never

show up in fossil record– Caution in comparing present extinctions with

past– Our choice

Future Earth?

Long-Term Climatic Trends

• Brightening of the Sun

• Capturing of CO2 by carbonate rocks?

• Moist greenhouse effect

• Runaway CO2 Greenhouse Effect

• Venus conditions

Planetary Habitable Zones

• Primarily in the Liquid Water Zone

• Can’t be too warm

• Water Vapor in upper atmosphere broken down by solar UV and charged particles (photodissociation)

• Hydrogen escapes to space

Planetary Habitable Zones

The Ultimate Long-Term Forecast

• Slow warming trend for the next billion years

• Increasing humidity

• CO2 decrease leads to extinction of plants?

• Boiling and evaporation of the oceans

The Oreo Model of Life History

• Micro-organism Earth (0-3 billion years)

• Multicellular Earth (3-5 billion years)

• Micro-organism Earth (5-6 billion years)

• “The white creamy middle”